Nepal’s weather is famously dramatic. In a single day you can move from warm, humid plains to snow-dusted alpine ridgelines. That variety comes from extreme changes in elevation across a small horizontal distance: tropical Terai in the south, montane and hilly middle country (the “hills”), and the high Himalaya in the north. Nepal’s year is usually divided into four main seasons:

Spring (March–May)
Summer/monsoon (June–September)
Autumn (September–November) and
Winter (December–February) — each with its own advantages and hazards for travellers.

Below is a practical, region-by-region guide to when to go and why, followed by month-by-month notes and packing/planning tips.

Quick seasonal snapshot (what to expect)

• Spring (Mar–May): Warming temperatures, rhododendron and wildflower blooms in the hills, excellent trekking (pre-monsoon), pollens increase in lowlands. Great mountain views on clear days.
• Monsoon / Summer (Jun–Sep): Heavy rain in most of the country, especially hills and lower Himalaya; humidity & heat in the Terai; travel disruptions and landslides are common. Not ideal for high-visibility mountain views or many treks.
• Autumn (late Sep–Nov): Post-monsoon clarity, dry stable weather, the most popular season for trekking and sightseeing; skies are often the clearest of the year.
• Winter (Dec–Feb): Cold in high places, pleasant to cool in the lower hills and Terai. High passes and many Himalayan treks are snowbound; valley sightseeing in Kathmandu is still possible and often sunny.

Himalayan region (Everest, Annapurna, Manaslu, Mustang, etc.)

Best times: Autumn (late Sep–Nov) and Spring (Mar–May).


Why: Autumn follows the monsoon and offers the clearest, dust-free skies and stable weather — perfect for panoramic mountain views and high-altitude trekking. Spring brings warmer daytime temperatures, rhododendron blooms at lower elevations and good conditions for climbing/trekking before the monsoon arrives. Both windows are also when lodges and services on the trails are fully operational.

When to avoid: Mid-June to September (monsoon) — heavy rainfall, leeches in lower hills, poor visibility and frequent landslides that can cut trails and roads. Deep winter (Dec–Feb) is cold and many high passes are closed by snow. Reuters and trekking sources note significant monsoon hazards (floods, landslides).

Special notes:

• If you want to attempt major climbs (Everest window) or witness summit seasons, late April–May is the main climbing window on many high peaks.
• For less crowded trekking (but colder and with variable access), consider winter routes at lower elevations (lower Annapurna circuits, lower Mustang) — expect frozen nights and limited services.

Hilly region (Kathmandu Valley, Pokhara, mid-hills)

Best times: Autumn (Sep–Nov) and Spring (Mar–May).


Why: Kathmandu and Pokhara see mild, pleasant daytime temperatures and excellent visibility in these seasons. Autumn coincides with major Nepali festivals (Dashain/Tihar), offering cultural experiences plus great weather for sightseeing and short hikes. Spring adds flowering hillsides and warmer days.

When to avoid: Monsoon months can bring heavy rain and muddy rural roads. In late winter (Dec–Feb), mornings can be chilly and foggy, though daytime sunshine is common. Air quality/pollution in Kathmandu can sometimes reduce views, particularly outside peak-clear months.

Special notes:

• Flights (including mountain sightseeing flights) and paragliding in Pokhara typically run more reliably during autumn and spring, when visibility is best.

Terai (Chitwan, Bardia, lowland plains)

Best times: October–March (dry/cool season).


Why: The Terai is tropical/subtropical: the cooler, dry months make wildlife safaris, walking, and jeep tours far more comfortable. Rivers are lower, and wildlife activity is visible in the cooler mornings and evenings. Responsible travel guides often recommend Oct–Mar for Chitwan National Park.

When to avoid: Mid-April–May (very hot) and Monsoon (June–September) when humidity, heavy rain, mosquitoes and muddy roads reduce comfort and accessibility. Some parks may have limited programs during heavy rains.

Month-by-month practical guide (short)

• January: Cold in mountains, clear skies but many high trails closed. Lowland sightseeing is pleasant.
• February: Gradually warming; early spring treks start in late Feb in lower altitudes. Good for fewer crowds.
• March–May (Spring): Excellent for trekking/trekking flora; climbing season ramps up in April–May. Expect warmer days.
• June–September (Monsoon): Heavy rain, landslide risk, limited mountain visibility. Best for lowland, jungle (if you don’t mind rain) or off-season bargains — but plan for disruptions. Reuters reporting highlights flood and landslide dangers in monsoon months.
• September–November (Autumn): Peak season — crystal-clear skies, stable conditions, festivals and full services. Most popular for treks and mountain flights.
• December: Cold at elevation; lower hills and Terai remain accessible and pleasant; winter trekking is possible at lower altitudes.

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Practical planning & packing advice (by season/region)

• Autumn & Spring (general): Layers (warm morning/evening, light daytime), good trekking boots, sun protection (hat, sunscreen), light rain shell for unpredictable showers in spring.
• Monsoon: Waterproof boots, heavy-duty rain jacket, quick-dry clothing, pack rain cover, mosquito repellent, flexible travel schedule. Expect road/flight delays.
• Winter (mountains): Insulated jacket, thermal layers, warm hat & gloves; many teahouse rooms have limited heating.
• Terai: Light clothing for daytime, a light sweater for cool mornings/winters, strong insect repellent in warm months.

Safety & logistics considerations tied to weather

• Roads & landslides: The monsoon significantly increases the risk of landslides and road closures in hilly and mountain districts; factor extra travel time or avoid travel during heavy rains. News reporting underscores that monsoon events can be deadly and disruptive.
• Flights: Mountain-visibility is best in autumn (and often spring). Domestic flights are more likely to operate on schedule in clear months; during monsoon/foggy winter mornings delays and cancellations increase.
• Health: Heat & humidity in the Terai during late spring/early summer increase discomfort; bring hydration and sun protection. Monsoon increases insect activity — bring repellents and consider preventive health advice (check vaccinations and health guidance for jungle areas).

Final tips & decisions by traveler type

• Peak-mountain-views / classic trekkers (Everest/Annapurna): Aim for Oct–Nov (best clarity) or Mar–May (warmer, flowering).
• Budget travellers / off-peak deals: Monsoon (Jun–Sep) can offer lower prices and fewer crowds — but accept higher risk of disruptions and muddy trails.
• Wildlife safaris & lowland comfort: Oct–Mar for Chitwan & Bardia—cool, dry and wildlife is easier to spot.
• Cultural & city sightseeing: Autumn is ideal — comfortable weather plus festivals (Dashain/Tihar) and vibrant cultural life in Kathmandu and towns.

Sources & further reading

Key sources used for this guide include Nepal’s tourism overview and climate pages, major trekking and travel authorities, regional climate data, and news reporting on monsoon hazards. Notable references: Nepal Tourism Board (climate overview), Switchback Travel / Lonely Planet (trekking seasons), Responsible Travel (Chitwan timing), Weatherspark (Kathmandu temps), and Reuters reporting on monsoon floods & landslides.